1. Field
The present invention is in the field of thermally isolating pixels and strengthening an uncooled staring focal plane array, and specifically a method of depositing an easily sublimateable backfill material in reticulated grooves of a detector material prior to bonding the detector material to a readout array and then sublimating the backfill material out of the grooves to leave air gaps between the detector elements.
2. Prior Art
A problem exists in thermally isolating detectors in uncooled detector focal plane arrays. Thermal crosstalk between adjacent elements significantly reduces the responsivity and modulation transfer function of these devices. Complete reticulation of these arrays is the ideal solution to this problem. However, the reticulation leaves the detectors as isolated cubes of material held together only by a top common electrode and an absorbing layer. The array is too fragile to withstand bonding to the readout array. A backfill material deposited in the reticulation grooves solves the structural weakness problem during the bonding prcess, but the backfill materials previously used are not easily removed after the detector array and readout array are bonded together. While some backfill materials improve the lateral heat transfer problem, none of these materials are as good as an air gap for preventing heat transfer.